Rotary bit



Nov. 26, 1929. A. E. vCARLSON ROTARY BIT Filedv Sept 7, 1926 3Sheets-Sheet l Nov. 26, 1929. A. E. CARLSON I ROTARY BIT 5 sheets-sheet'2 led Sept. 7, 1926 A mw.

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l Afr TORNEYT Nov. 26, 1929. A, E, CARLSON 1,737,215

ROTARY BIT Filed sept. 7, 192e s sheets-sheet 5 55-f w WWU' /55 mi h.5155 n 1h l lulu A7" TORNE x Patented Nov. 26, 1929 UNITED STATES PFFME .ANTHONY n. cARLsoN, or Los ANGELES, cALIFoRNIA ROTARY BITApplication vled September 7, 1926. Serial No. 133,836.

' secured at the lower end of adrill pipe. This drill pipe extends -tothe surface of the ground and is rotated by means of a rotary tablesituated in the derrick of the well. As

the rotary cutter is rotated, the bottom of the hole is cut away. Thereare two types of cutters commonly used in this system, the flat drillwhich includes fishtail and diamondpoint drills, and drills havingrotating cutters" `projections thereat which readily splinter or crumbleaway as the bit is rotated.

Tt is another object of my invention to provide a rotary bit of thischaracter which will not form cores during drilling operations. A coreis a formation which is formed and extends upwardly between the cuttersof a bit asa hole is sunk. This core interferes with the drilling of thehole by its engagement with the lower portion of the body of the bitbetween the cutters. When drilling through extremely hard formations,this core will not crumble away when it engages the body of the bit andconsiderable interference to the drill is occasioned. lThis interferenceeither greatly retards the drilling7 or it deflects the drill bit to oneside, thus causing a crooked hole t0 be drilled. In my invention Tarrange the cutters of my bit in such a position that one of vsaidcutters operates over the center of the holev being drilled, thuseliminating formation of any core whatever.

It is also an object of my invention to provide a drillbit of thischaracter which is .superior to other bits, inasmuch as it is extremelysimple in construction, has few parts, 'and is very rugged, so that itmay endure great strains. l

It is a further object of my invention to provide a rotary disc bit ofthis character having a unique cutter support. The cutter supportprovided by my invention is preferably provided in an integral member'vadapted to be secured to a body of the bit. This integral member has adepending central wall,

from which vcutter supporting arms extend in different directions. Thecutters of the bit are first placed upon the cutter supporting arms andthen the cutter support is installed in place in the body. Theconstruction of the cutter supporting arms is such that they engage thebody in such a manner as to lock the cutters in place. The salientadvantages of a construction of this character are that there are lessparts to the bit; the parts are massive, and consequently very strongand yvarious parts are very facile to install and remove.. y

It is also an object of my invention to provide a rotary bit of thischaracter in which it ispractically impossible to lose any of the parts.During the operation ,of a present type of drill, the parts of the bodycarrying the cutters are sometimes worn away to the extent that thecutters are lost. 'My bit is so constructed that .it is impossible forthe cutter supporting parts to wear in such a manner as to permit theirbeing lost. v

Other objects and the especial advantages of my invention will be madeevident inthe following description.

Referring to the three sheets of drawings in which I illustrate apreferred embodiment of my invention,

Fig. 1 is a diagrammatic' View illustrating the utility of my invention.

Fig. 2 is a vertical sectional view of a drill bit embodying thefeatures of my invention.

Fig. 3 is a vertical sectional view through the bit shown in Fig. 2,this view being taken substantially on the line 3-3 of Fig. 2.

4 Fig. `l is a horizontal cross. section taken through the cuttercarrying arms and the cutu -tersof my invention, this View being takensubstantially on a plane indicated by the lines 4 4 of Figs. 2 and o.

-Fig. 5 is a horizontal cross sectional view taken on a plane indicatedby the line 5-5 of Fig. 3.

Fig. 6 is a View showing the novel form of bearing bushing employed inmy invention, this view being taken on a plane as indicated by the line6 .6, of Fig. 4. Fig. 7 is a vertical cross sectional view taken throughthe body of the bit of my in# vention. y

Fig. 8 is a perspective view clearly illustrating the construction ofcutter support provided by my invention.

With particular reference to Fig. 1,` I show a rotary bit 11, whichembodies the features of my invention, sinking a well 12. The rotary bit11 is secured at the lower end of a drill pipe 13 which extends upwardlythrough the well 12 to the surface of the ground. On a derrick 14 ofthewell 12 is a rotary table 15 which engages the pipe, as shown, for the ipurpose of giving rotation thereto in a manner to rotate the rotary bit11, 'thus sinking4 the well 12. A traveling block 17 Ais provided bywhich the drill bit 11 is fed downwardly as the Well is drilled. Rotarymud is forced downwardly through' the drill pipe 13 to the bit 11 bymeans of a pressure pump 18, which is connected to the upper end of thedrill pipe 13 by mea-nsof a stand pipe 20, a hose 21 and a swivel head22, this pressure pump 18 obtaining its supply of rotary mud from a sump23 through a pipe 23.

The rotary bit 11 embodying the features of my invention is clearlyshown in Figs. 2 to 8, inclusive, of the drawings. With particularreference to Figs. 2 and 3, the bit 11 is provided in the form of a body24 to which is-secured acutter support 25. As clearly shown in Fig. 7,the body 24 has a threaded pin 26 which is adapted to thread into a box27 of a tool joint 28, which tool joint as shown in Fig. 1 is attachedat the lower end of the drill pipe 13. Opening from the bottom of thebody 24 is a shoulder cavity 30, this cavityor borehaving a cylindricalportion 31 and a cylindrical portion 32, between which a shoulder 33 isformed. Diametrically oppositeilegs 35 depend .from the body 24.. .Theselegs 35, as shown in Fig. 7, have notches'37 which provide bearing facesv38. Diametrically opposing-legs 40 also depend from the body 24, theselegs being spaced at substantiahlly ninety degrees with respect to thelegs 35. The legs 40 have notches 41 which provide upper bearing facesl42. Y

The cutter support 25, as clearly shown in Fig. 8, has a shoulderedportion 46 which is provided in the form of cooperating cylinders 47 and48, between which there is provided a shoulder 49. As clearly shown inFigs. 2and 3, the support is installed in the body 24 in such a mannerthat the cylinder 47 extends into the portion 31 of the cavity 30,

. the cylinder -48 extends i'nto the portion 32 of the cavity 30, andthe shoulder 49 of the sup- .4 and 8, the central wall 53 rests in aplane slightly to one side of the axis of rotation of the bit, thiscentral wall extending parallel 'with and to one side of a line A-A ofFig. 4, which line A-A passes through the axis of.' the bit. Angledcutter arms 54'extend out- Wardly from this central wall 53 in thedirection of extension thereof, these angled cutter arms being square incross section, as is evident from Fig. 8. The arms '54 extendoutwardlyin the same vertical plane but extend Vat angles relative toeach other with respect to a horizontal plane. As is clearly evident inFig. 4, the arms 54 are oEset slightly with respect to the dependingcentral wall 53 so as to extend centrally on the plane A-A, whichextends through theaxis of rotation ofthe bit. Straight cutter arms 56extend from rthe depending central wall'53 substantially' at rightangles to the extension thereof. These straight cutter arms are squarein cross section and extend in a plane B-B of Fig. 4, which planeextends through the axis .of rotation of the bit, these arms 56 being inalignmentvin a vertical plane and also in a horizontal plane.

On each of the arms 54 and 56 bearing bushings 58 are placed. As clearlyshown in Fig. 6, these bearing bushings have alrectangular opening 59,through which one of the arms 54 or 56 extends; therefore, the bearingbushings 58 are non-rotatable with respect to the arms 54 or 56. Thebushings 58, however, have a cylindrical outer bearing face 60. On thebushings 58 of the arms 56 are placed cone cutters 63 and 64. 'The conecutter 63 is provided with axial teeth, whereas the cone cutter 64 isprovi-ded with circumferential teeth.

Between the faces 62 of the central wall 53 and the inner ends ofthecone cutters 63 and 64, I place wear plates 65. Between the legs 40 andthe outer ends of the cone cutters 63 and 64 I place wear plates 66.rThe outer ends 67 of the arms 56, as clearly shown in Fig.

3, extend into notches 41 in the legs 40, and the upper faces thereofengage with the bearing facesi42 of the notches 41. On the bearingbushings 58 ofthe angled cutter arms 54, I place,.as shown in Fig. 2,cylindrical cutters 69 and 70.v VThe cutter 69 has circumferential teethand the cutter 70 has axial teeth. Be. tween the edges 71 of the centralwall 53 and the inner ends of the cutters 69 and 70 I place wear plates72, and between the legs 35 of the body 24- and the outer ends of thecutters 69 and 7 0 I place wear plates 73. Asis evident from Fig. 2, theanvularity of the cutter arms 54 disposes the cylindrical cutters 69 and70 on angles also. The outer ends of the angled arms 54 are iattened at74 and extend into the notches 37 of the legs 35 so that the faces 74 ofthe arms 54 engage the bearing faces 38 provided by the notches 37.

The cone cutters 63 and 64 are arrangedl fairly close together and maybe. considered as inner cutter members. The inner end of the cone cutter63 extends over the center of the hole being drilled; that is, itextends over a point directly below the axis of rotation of the bit.This is possible due to the offsetting of the depending Wall 53 to oneside of the axis A-A of Fig. 4. The purpose of this will be explainedlater. The cylindrical cut- 78 formed in the body 24 and fluidpassages*v 79 formed in the support 25, there being a passage for eachof these cutters, as is evident from F ig. During the operation of thebit -11 in the well 12, rotary mud is forced by the pressure pump 18downwardly through the drill pipe 13, this rotarymud passing out of thepassages 7 9 of the support 25, thus washing the teeth of the cuttersand the surface against which the cutters are Working. This rotary mudHows upwardly and carries with it to the surface of the well cuttingsproduced by the bit.

The feature of providing cutters having axial and circumferential teethis a very im portant vconsideration of my invention. As the bit 11rotates, the cutters 63 and 70 engage thesurfac-e against which they arecutting in such a. manner as to cut radially extending grooves orrecesses therein. The circumferential toothed cutters 464 and 69 engagethe bottom of the hole and produce ,circular grooves or recessestherein. It is evident that the combined 4'cutting yof the radial teethand the circumferential teeth produces a checkered surface';'that is,the bottom of the hole is cut in such a manner that a multiplicity ofpyramid-shaped projections extend 'therefrom. As the action of thesecutters opntinues, the projections formed thereby readily splinter andcrumble away. The teeth ofthe cutters are never entirely embedded in thematerial being cut, due tothe cross direction of cutting of the two setsof cutters. This arrangement makes the drilling, especially through hardmaterial, much 'quicker than directly over the center of thehole. Bythis 70 provision there is no central projection or core formation whichmight interfere with 'the progress of the bit. This constructionentirely prevents the forming of any cores which might hinder and retardthe drilling 75 of a hole.

The ease with which the few parts of my bit may beassembledis also aprominent consideration of the invention. From the installing of thesupport 25, the bearing bushings 58 and the cutters 63, 64, 69 ,and 7 0are installed on cutter carrying arms 54 and 56. The support is theninstalled in 'place as drawings it is evident that previous to the S0shown in Figs. 2 and 3, and the securing pin g5 50 is then extended intoplace as shown in Fig. 5. lWhen the support 25 is thus in stalled, theends of the cutter carrying arms 54 and 56 extend into the notches 37and 41, l

respectively, the upper edges thereof engag- 90 ing with the bearingfaces provided by the legs 'of the body'24. It will be vseen that whenthe support 25 is in place, the legs 35 and retain the cutters in theirproper positions. Likewise, to remove or to replace the 95.

cutters of the bit, it is conveniently done by removing the pin whichallows the removal of the disc support 25. When the disc support 25 hasbeen separated from the body 24, it leaves the cutters free to beremoved from the ends of the arms 54 'and 56.

In some of the present types of rotary bits, it often occurs 'that thebody of these bits wears to the extent .that certain of the cutter partsare lost.

24 to wear down a distance equal to the thick- :nessk of the legs 35 or40. A wearing to this extent is absolutely impossible. My bit'has 11.0

but very few parts which are very rugged ,j and cheap to manufacture.

This is a'continuation in part of my application entitled Rotarybit,1riled December 27,

1924, SerialNo. 758,376. A 1.1.5

As is evidenced from the drawings, before any part of my bit can belost, it will be necessary for the enti-re body transversely projectingcutter carrying armsv extending below said shouldered portion and`vangled relative to a horizontal plane,'an`d`"`125 transverselyprojecting horizontal cutter carrying arms extending below saidshouldered portion; cutters carried by said angled and said .horizontalcutter carrying arms and means-,at tlieglefweiend of said body for en-13o supporting means,

gaging at least one of said cutter carrying cutting arms.

2. A drill bit as delined in claim 1 in which the body is provided withrelatively spaced body, transversely projecting cutter carrying armsextending below said shouldered portion and angledv relative to ahorizontal plane, and transversely projecting horizontal cutter carryingarms extending below said shouldered portion, said .critter carryingarms being square in cross section; bearing bushings carried by saidcutter carrying arms, said bearing bushings having a square openingthrough which said arms extend and having a cylindrical external face;and vcutters carried by said bearing bushings.

4. In a drill bit of the class described, the combination of: a body;supporting means carried by said body; inner conical cutters carried bysaid supporting means, said inner conical cutters being diametricallydisposed in relation to said body,'one of said inner cutters havingaxial teeth and the other of said inner cutters having circumferentialteeth; and outer cylindrical cutters carried by said supporting means,said outer cutters being disposed on opposite sides of and arranged atright angles to said inner conical cutters, one of said outer cuttershaving axialtect-h and the other of said outer cutters havingcircumferential teeth.

5. In a drill bit of the class described, the combination of: a body;supporting means carried by vsaid body; inner conical cutters carried bysaid supporting means, said inner conical cutters being diametricallydisposed in relation to said body, one of said inner cutters havingaxial teeth and the other of said inner cutters having circumferentialteeth; and outer cylindrical cutters carried by said said outer cuttersbeing disposed on opposite sides of and arranged at right angles to saidinner conical cutters, one of said outer cutters having axial teeth andthe other of said outer cutters having circumferential teeth, one ofsaid inner cutters having axial teeth extending adjacent to the axis ofrotation of the bit.

6. Acutter support for a drill bit of the class described, comprising: avertical shank having a depending portion provided with a plurality ofrelatively spaced transversely projecting cutter supporting arms adaptedto Y 'extend into cutters mounted thereon and arranged inthe form of atransversely disposed cross, said arms being square in `cross section.

7. A cutter support fora drill bit adapted for insertion into a drillbody,v the whole to be secured to a drill pipe, comprising: a verticalshank having a depending portion provided With a plurality of relativelyspaced transversely projectingA cutter supporting arms adapted to extendinto cutters mounted thereon and arranged in the form of a translversely disposed cross, each alternate arm beinoP disposed in ahorizontal plane and each Vintermediate arm being disposed at an angleto a horizontal plane, said arms being polygonal in cross section.

8. In a drill bit of the class described, the

combination of: a body having a bore extending upward from its lowerend, said body be; ing'adapted to be secured to' a drill pipe; a

- cutter support having a shank extending into said bore and a dependingportion provided with transversely projecting horizontal'c'utter,carrying arms and other transversely projecting arms angled relative toa horizontal plane; cutters carried by said arms; and means for securingsaid support to said body so as to maintain the same substantiallywithin the bore.

9. In a drill bit of the class described, the combination of a bodyhaving a bore extending upward from its lower end; a cutter supporthaving a shank extending into said bore and a depending portion providedwith transversely projecting horizontal cutter carrying arms and othertransversely projecting arms angled relative to a horizontal pla-ne.;cutters carried by said arms; and: means for securing said'support tosaid body, said body havingyelatively spaced depending legs, eachengaging one of the arms of said support.

10. In a drill bit of the class described, the

notched at its lower end, to receive the outer end of one of the arms ofsaid support.

12. In a drill bit of the class described, the combination ot: a bodyhaving a bore extending upward from its lower end; said body beingadapted to be secured to a drill pipe, a cutter support having a shankextending yinto said bore and a depending portion provided withtransversely-projecting horizontal cutter carrying arms and othertransversely projecting arms angled relative to a horizontal plane;bearing bushings nonro tatably mounted'on said arms; cutters'journaledon the respective bushings; means for spaced depending legs, eachvertically securing said support to saidbody and means carried by saidbody for engaging saidarms.

13. A drill bit as defined in claim 12 in which the body is providedwith relatively spaced depending legs, each vertically notched at itslower end, to receive the outer end of one of thearms of said support.

14. In a drill bit of the class described, the combination of: a body; acutter support se- Acured to said body, said cutter support comprising ashouldered portion adapted for insertion into a shouldered cavity ofsaid body, transversely projecting cutter carrying arms extending` belowsaid shouldered portion and angled relative to a horizontal plane, and`transversely projecting horizontal cutter carrying arms extending belowsaid shouldered portion; bearing bushings non-rotatably mounted on saidarms; cutters carried j by said bearing bushings and means carried bysaid body for engaging said arms.

l 15. A body for a drill bit of the class described having an axial boreextending upward from its lower end and provided with relatively spaceddepending legs disposed around said bore, the lower ends of said legseach being provided with a vertically disposed notch, said bore and saidnotches being adapted to receive a cutter supporting means, the innersurfaces of an opposite pair of said legs being vertically disposed andrelatively parallel, and the inner surfaces o f another pair of saidlegs diverging downward and outward.

16. In a cutter support for a drill bit of the class described, thecombination of: a plurality of pairs of rotary cutter supporting arms,the arms of each pair being disposed on opposite sides ofthe axis of thebit from each other; and-an eccentric web connecting the inner ends ofsaid arms.

17. A combination as in claim 16 in which said arms are 'disposed tosupport cutters so that the axes of rotation of said cutters intersectthe axis of the bit. A

18. A combination as in claim 16 in which the inner end of one of saidarms extends relatively close to the axis of the bit so that a cuttermounted on said arm cuts closer to the center of the hole than any ofthe cutters mounted on the other of said arms.

19. In a drill bit a cutter assembly comprising: a cutter support; twoprimary arms proj ectiiig from the sides of said cutter support; twosecondary arms projecting from the ends of said cutter support; a bodyhaving a bore extending upwardly from its lower end, means for securingsaid cutter support to said body, and maintaining it substantiallywithin the bore, and cutters mounted on all said arms in operativeposition.

20. In a drill bit of the class described, the combination of: a bodyhaving a bore extending upwardly from its lower end, a cut ter supporthaving a shank extending into

